Cider vs beer. Stomach irritation and burning

M25 for reference. Had barely any money to last me until payday recently and swapped spirits for cheap 2 liter bottles of cider. Would drink maybe 4 - 6 liters of that horrible stuff a day. Not much water and skipping meals throughout the day. Would wake up with stomach pains, agony when urinating etc. 2 days ago I decided to quit the cider, it was agonising, for weak lagers. The cans slowed my pace down and I'd drink water between. I also ate proper home cooked, natural whole food meals. After 24 hours I woke up and felt more refreshed, not as painful when weeing, less groggy and overall better.

I know the science behind cider vs weaker beer etc. Less acidic, lower sugar, hydrating with additional water but wonder if anyone else has similar experience quitting the sweet, sweet cider.

Small steps...